A majority of malocclusions involve some discrepancy in the position of the upper teeth relative to the lower teeth. Either the upper or lower teeth may be protruded or retruded relative to each other. Because these types of malocclusion cannot be corrected by braces alone, different types of force modules have been used that attach to the patient's braces that in conjunction with the braces deliver the proper force to correct these problems. Until fairly recently these force modules have consisted mainly of headgear and elastics, which are placed onto the braces by the patient. Unfortunately, the lack of patient cooperation in wearing removable devices severely limits the predictability of their results.
More recently, intraoral devices that connect to the patient's braces have been introduced. These devices eliminate the need for patient cooperation, however they introduce other problems. There are two types of these interarch devices; the rigid piston rod and cylinder type and the flexible spring type. Relevant issued patents of which the inventor is aware include U.S. Pat. Nos. 5,752,823; 5,562,445; 3,798,773, 4,708,646; and U.S. Pat. No. 5,435,721. The rigid type devices disclosed in these patents have the advantage of being more durable but they are bulkier and interfere with normal oral function. The patient better tolerates the flexible type but they are more prone to breakage and they limit the patient's range of jaw motion.
Therefore, although there are a variety of interarch devices for correcting anterior-posterior tooth discrepancies, there is a continued need in the art to improve existing options and to provide new devices that function more reliably while increasing patient comfort.